Nathan Visscher didn't know he was about to save a fellow surfer's life when he went for an afternoon surf on January 18 last year.

Visscher was in the water at Redhead Beach when he noticed Glen ''Lenny'' Folkard struggling and crying for help after being bitten by a 3.1-metre bull shark.

He spoke to 1233's Aaron Kearney about his heroic act after it was announced that he would receive a prestigious bravery medal.

"The day before the shark attack there were a bunch of us sitting round and having a few drinks, and we were actually talking about what you would do if someone near you was attacked by a shark, and how would you handle it," said Visscher.

"Funnily enough, the next day it happened."

While waiting for a wave with a group of other surfers, Visscher heard a cry for help 20-metres away.

"It was quite loud and I turned around and noticed Lenny was half-off his board, scrambling to get back on."

At first he thought Folkard had a leg-cramp and had "gone a bit overboard" but Visscher realised that the situation was serious when a large chunk of white foam surfaced next to Folkard.

A shark had bitten through his leg and surf board, leaving a trail of blood.

"At this stage the shark had swum about 3 or 4 metres away from him, turned around and was slowly heading back towards him," said Visscher.

"There was a bit of frantic commotion, everyone paddling to get on a wave. I thought about it, I looked back at Lenny and I just felt really sorry for him - it could have been me."

Visscher paddled as fast as he could toward the injured man, with the figure of the shark visible beneath the waves. Other surfers swam back to the beach.

"I kind of thought the shark was going to have another go at him, and I thought I don't really want to witness this - I can't watch this shark maul this guy to death"

"I thought to myself, what happens if he drowns and doesn't die because of the wounds, and I hadn't have gotten hold of him?"

Putting himself in the line of attack, Visscher grabbed Folkard on the shoulder and gave him a squeeze.

"I still remember this vivid image, when he turned to me his eyes were as big as golf balls, the colour was completely drained from his face and he said to me 'the bugger got my leg, please don't leave me, I don't want to die."

Together they caught waves into the beach where Folkard was treated by medical personnel and taken to hospital. He later underwent six operations and numerous skin grafts on his right thigh and buttock area.

Prior to the events Visscher and Folkard didn't know each other, other than a head nod and a "how you going" at the beach.

Now Visscher has "gained a good friend" and is even considering taking up Folkard's offer for a free tattoo at his Belmont tattoo parlour.

The Redhead hero's considerable bravery has now been officially recognised by the Australian Bravery Decorations Council with a Bravery Medal.